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United States Patent | 6,149,319 |
Richter ,   et al. | November 21, 2000 |
A method and apparatus for maintaining the voltage level of data signals supplied to an integrated circuit, such as a PCMCIA card, at the same level as power also provided to the integrated circuit. Circuitry for maintaining the voltages at the same level is preferably embodied within a system having a card controller integrated circuit, a power supply, and a peripheral card socket for receiving a removable PCMCIA card. The power supply is controlled by the card controller to provide power to the PCMCIA card through the card socket at a voltage level matching internal voltage requirements of the PCMCIA card. The card controller is connected directly to the PCMCIA card by a signal transmission line. Circuitry is provided for ensuring that the voltage of data signals transmitted along the data bus line to the PCMCIA card substantially match the voltage of power provided from the power supply to the PCMCIA card along a power supply line. In this manner, damage resulting from a power mismatch within the PCMCIA card is avoided.
Inventors: | Richter; Bryan M. (Fremont, CA); Smith; Stephen A. (Palo Alto, CA); Assar; Mike (Morgan Hill, CA); Kashmiri; Abdul Q. (Fremont, CA); Clark; Jerry L. (Fremont, CA); Singhal; Dave M. (San Jose, CA) |
Assignee: | Cirrus Logic, Inc. (Fremont, CA) |
Appl. No.: | 388615 |
Filed: | February 14, 1995 |
Current U.S. Class: | 713/300; 713/340 |
Intern'l Class: | G06F 001/26 |
Field of Search: | 395/750,281,282,283,311,750.08,750.06 364/707 235/490 |
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